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Properties of jets in high-E/sub T/ events produced in pp collisions at. sqrt. s = 63 GeV (open access)

Properties of jets in high-E/sub T/ events produced in pp collisions at. sqrt. s = 63 GeV

The properties of jets in high-E/sub tau/ events produced in pp collisions at ..sqrt..s = 63 GeV have been studied at the CERN Intersecting Storage Rings. The fragmentation of the jets is found to be similar to that of jets produced in e/sup +/e/sup -/ annihilation. The jets are wider than calculated from a constituent scattering model with no hard bremsstrahlung component. The charge correlations of positive and negative particles show differences consistent with expectation from valence-quark scattering. 11 references.
Date: July 1, 1983
Creator: Akesson, T.; Albrow, M.G.; Almehed, S.; Batley, R.; Benary, O.; Boggild, H. et al.
System: The UNT Digital Library
NCIS - a Nuclear Criticality Information System (overview) (open access)

NCIS - a Nuclear Criticality Information System (overview)

A Nuclear Criticality Information System (NCIS) is being established at the Lawrence Livermore National Laboratory (LLNL) in order to serve personnel responsible for safe storage, transport, and handling of fissile materials and those concerned with the evaluation and analysis of nuclear, critical experiments. Public concern for nuclear safety provides the incentive for improved access to nuclear safety information.
Date: July 1, 1983
Creator: Koponen, B. L. & Hampel, V. E.
System: The UNT Digital Library
Production of antihyperons in the central region at the ISR. The axial field spectrometer collaboration (open access)

Production of antihyperons in the central region at the ISR. The axial field spectrometer collaboration

We present measurements of the relative production cross-sections of anti p, anti ..lambda.., anti ..xi.., and anti ..cap omega.. at y approx. 0 for 1 less than or equal to p/sub T/ less than or equal to 2 GeV/c in pp collisions at ..sqrt..s = 63 GeV. The results are compared with previous measurements of antibaryon production in hadronic and e/sup +/e/sup -/ collisions.
Date: July 1, 1983
Creator: Akesson, T.; Albrow, M.C.; Almehed, S.; Batley, R.; Benary, O.; Boggild, H. et al.
System: The UNT Digital Library
Volume generation of negative ions in high density hydrogen discharges (open access)

Volume generation of negative ions in high density hydrogen discharges

A parametric survey is made of a high-density tandem two-chamber hydrogen negative ion system. The optimum extracted negative ion current densities are sensitive to the atom concentration in the discharge and to the system scale length. For scale lengths ranging from 10 cm to 0.1 cm optimum current densities range from of order 1 to 100 mA cm/sup -2/, respectively.
Date: July 1, 1983
Creator: Hiskes, J.R. & Karo, A.M.
System: The UNT Digital Library
Comparison between experimental and theoretical results for the fast-head-tail instability in PEP (open access)

Comparison between experimental and theoretical results for the fast-head-tail instability in PEP

The fast-head-tail instability has been observed at several storage rings. This is a single-bunch beam instability where the unstable motion can occur in either the horizontal or vertical plane. Kohaupt and Talman have offered a simplified treatment of this instability by modeling the bunch as two rigid macroparticles executing synchrotron oscillations and thus exchanging their longitudinal positions periodically. While the wake field forces which drive the fast-head-tail instability are the same ones which drive the slow-head-tail instability, the growth mechanism is considerably different. The two particle model describes the particle motion with two normal modes; below a certain stability threshold, these two modes are stable with different frequencies. In the limit of zero beam current only one of these modes has a center-of-charge motion. However, as the current is increased, both modes acquire center-of-charge motions and at threshold the center-of-charge components of their motions become equal in magnitude, thus when the center-of-charge motion is excited by an impulse as by an injection kicker, the relative amplitude of the two modes depends upon the ratio of bunch current to the threshold current. We shall describe the character of this coherent motion both theoretically and experimentally.
Date: July 1, 1983
Creator: unknown
System: The UNT Digital Library
Exploration and development of the Cerro Prieto geothermal field (open access)

Exploration and development of the Cerro Prieto geothermal field

A multidisciplinary effort to locate, delineate, and characterize the geothermal system at Cerro Prieto, Baja California, Mexico, began about 25 years ago. It led to the identification of an important high-temperature, liquid-dominated geothermal system which went into production in 1973. Initially, the effort was undertaken principally by the Mexican electric power agency, the Comision Federal de Electricidad (CFE). Starting in 1977 a group of US organizations sponsored by the US Department of Energy, joined CFE in this endeavor. An evaluation of the different studies carried out at Cerro Prieto has shown that: (1) surface electrical resistivity and seismic reflection surveys are useful in defining targets for exploratory drilling; (2) the mineralogical studies of cores and cuttings and the analysis of well logs are important in designing the completion of wells, identifying geological controls on fluid movement, determining thermal effects and inferring the thermal history of the field; (3) geochemical surveys help to define zones of recharge and paths of fluid migration; and (4) reservoir engineering studies are necessary in establishing the characteristics of the reservoir and in predicting its response to fluid production.
Date: July 1, 1983
Creator: Lippmann, M. J.; Goldstein, N. E.; Halfman, S. E. & Witherspoon, P. A.
System: The UNT Digital Library
1. 2-GeV damping-ring complex for the Stanford Linear Collider (open access)

1. 2-GeV damping-ring complex for the Stanford Linear Collider

The choice of parameters, the design, a 2-1/2 year consruction program and the early operation of a high field, high tune research and development damping ring complex for one of the two linear collider beams are described.
Date: July 1983
Creator: Fischer, G. E.; Davies-White, W.; Fieguth, T. & Wiedemann, H.
System: The UNT Digital Library
Synthetic H-R diagrams as an observational test of stellar evolution theory (open access)

Synthetic H-R diagrams as an observational test of stellar evolution theory

Synthetic H-R diagrams are constructed from a grid of stellar models. These are compared directly with observations of young clusters in the LMC and SMC as a test of the models and as a means to determine the age, age dispersion, and composition of the clusters. Significant discrepancies between the observed and model H-R diagrams indicate the possible influences of convective overshoot, large AGB mass-loss rates, and the best value for the mixing length parameter.
Date: July 1, 1983
Creator: Mathews, G. J.; Becker, S. A. & Brunish, W. M.
System: The UNT Digital Library
650 mm long liquid hydrogen target for use in a high intensity electron beam (open access)

650 mm long liquid hydrogen target for use in a high intensity electron beam

This paper describes a 650 mm long liquid hydrogen target constructed for use in the high intensity electron beam at the Stanford Linear Accelerator Center. The main design problem was to construct a target that would permit the heat deposited by the electron beam to be removed rapidly without boiling the hydrogen so as to maintain constant target density for optimum data taking. Design requirements, construction details and operating experience are discussed.
Date: July 1, 1983
Creator: Mark, J.W.
System: The UNT Digital Library
Self-pumping impurity by in-situ metal deposition (open access)

Self-pumping impurity by in-situ metal deposition

A system for in-situ removal of helium trapping in freshly deposited metal surface layers of a limiter or divertor has been studied. The system would trap helium on a limiter front surface, or a divertor plate, at low plasma edge temperatures, or in a limiter slot region, at high edge temperatures. Fresh material, introduced to the plasma and/or scrape-off zone, would be added at a rate of about five times the alpha production rate. The material would be reprocessed periodically, e.g. once a year. Possible materials are nickel, vanadium, niobium, and tantalum. Advantages of a self-pumping system are the absence of vacuum ducts and pumps, and the minimization of tritium processing and inventory.
Date: July 1, 1983
Creator: Brooks, J. N. & Mattas, R. F.
System: The UNT Digital Library
Theoretical calculation of rapid x-ray transients and radius expansion (open access)

Theoretical calculation of rapid x-ray transients and radius expansion

We present a calculation of a thermonuclear runaway on a 10 km neutron star which produces two x-ray bursts separated by approx. 2500 sec.
Date: July 1983
Creator: Starrfield, S.; Sparks, W.; Truran, J. & Kenyon, S.
System: The UNT Digital Library
Planar Channeling Radiation From Relativistic Positrons and Electrons in LiF (open access)

Planar Channeling Radiation From Relativistic Positrons and Electrons in LiF

Channeling radiation has been measured for planar-channeled 54- and 83-MeV positrons and 17-, 31-, and 54-MeV electrons in the ionic crystal LiF. The results are shown to be in reasonable, but not perfect, agreement with the results of many-beam calculations based upon a model of the crystal as an array of isolated Li/sup +/ and F/sup -/ ions.
Date: July 1, 1983
Creator: Berman, B. L.; Datz, S.; Fearick, R. W.; Swent, R. L.; Pantell, R. H.; Park, H. et al.
System: The UNT Digital Library
Lethal, potentially lethal lesion model (open access)

Lethal, potentially lethal lesion model

A theoretical framework to describe the formation of lethal mutations by radiation is presented. Lesions that are repaired (and misrepaired) in each type of experiment described (delayed plating and split dose) are assumed to be the same. In this model the same (potentially lethal) lesions cause both sublethal and potentially lethal damage. Potentially lethal damage is defined as damage which may be modified by alterations in postirradiation conditions. Sublethal damage is cellular damage whose accumulation may lead to lethality. A crucial consideration in the expression of the damage is the kind of medium in which the cells are placed during the repair period. Fresh or growth medium (F-medium) is assumed to cause fixation of damage after about 3 hours, while no fixation (only misrepair) occurs in conditioned medium (C-medium).
Date: July 1, 1983
Creator: Curtis, S.B.
System: The UNT Digital Library
Construction and operational experience of the Tandem Mirror Experiment-Upgrade (TMX-U) (open access)

Construction and operational experience of the Tandem Mirror Experiment-Upgrade (TMX-U)

The Tandem Mirror Experiment-Upgrade (TMX-U) incorporates two new features at Lawrence Livermore National Laboratory (LLNL) tandem mirror program, thermal barriers in the end plugs and injection of the neutral beams at several oblique angles. The thermal barriers isolate the electrons in the end plugs from those in the central cell, making it possible to heat them independently with microwaves. In addition, this innovation produces a large potential gradient in the end plugs with lower magnetic fields and lower neutral-beam energies than would be possible in a conventional tandem mirror device. The TMX-U is also designed to test neutral-beam-injection angles as an experimental parameter. We use angles other than 90/sup 0/ to produce a plasma with improved microstability.
Date: July 1, 1983
Creator: Chargin, A. K.; Calderon, M. O. & Moore, T. L.
System: The UNT Digital Library
Stress-corrosion cracking in BWR and PWR piping (open access)

Stress-corrosion cracking in BWR and PWR piping

Intergranular stress-corrosion cracking of weld-sensitized wrought stainless steel piping has been an increasingly ubiquitous and expensive problem in boiling-water reactors over the last decade. In recent months, numerous cracks have been found, even in large-diameter lines. A number of potential remedies have been developed. These are directed at providing more resistant materials, reducing weld-induced stresses, or improving the water chemistry. The potential remedies are discussed, along with the capabilities of ultrasonic testing to find and size the cracks and related safety issues. The problem has been much less severe to date in pressurized-water reactors, reflecting the use of different materials and much lower coolant oxygen levels.
Date: July 1, 1983
Creator: Weeks, R.W.
System: The UNT Digital Library
Design of the SLC damping ring to linac transport lines (open access)

Design of the SLC damping ring to linac transport lines

The first and second order optics for the damping ring to linac transport line are designed to preserve the damped transverse emittance while simultaneously compressing the bunch length of the beam to that length required for reinjection into the linac. This design, including provisions for future control of beam polarization, is described.
Date: July 1, 1983
Creator: Fieguth, T. H. & Murray, J. J.
System: The UNT Digital Library
Nova laser assurance-management system (open access)

Nova laser assurance-management system

In a well managed project, Quality Assurance is an integral part of the management activities performed on a daily basis. Management assures successful performance within budget and on schedule by using all the good business, scientific, engineering, quality assurance, and safety practices available. Quality assurance and safety practices employed on Nova are put in perspective by integrating them into the overall function of good project management. The Nova assurance management system was developed using the quality assurance (QA) approach first implemented at LLNL in early 1978. The LLNL QA program is described as an introduction to the Nova assurance management system. The Nova system is described pictorially through the Nova configuration, subsystems and major components, interjecting the QA techniques which are being pragmatically used to assure the successful completion of the project.
Date: July 18, 1983
Creator: Levy, A.J.
System: The UNT Digital Library
Silicon switch development for optical pulse generation in fusion lasers at Lawrence Livermore National Laboratory (open access)

Silicon switch development for optical pulse generation in fusion lasers at Lawrence Livermore National Laboratory

We have been developing a silicon photoconductive switch for use as a Pockels cell driver in the pulse generation systems of the fusion lasers Nova and Novette. The objective has been to make 10 kV switches repeatably and which are reliable on an operating system. We found that nonlinear phenomena in nearly intrinsic silicon caused excessive conduction at high voltage resulting in breakdown. Our experiments with doped material show that this problem can be eliminated, resulting in useful devices.
Date: July 12, 1983
Creator: Wilcox, R. B.
System: The UNT Digital Library
Inertial effects in laser-driven ablation (open access)

Inertial effects in laser-driven ablation

The gasdynamic partial differential equations (PDE's) governing the motion of an ablatively accelerated target (rocket) contain an inertial force term that arises from acceleration of the reference frame in which the PDE's are written. We give a simple, intuitive description of this effect, and estimate its magnitude and parametric dependences by means of approximate analytical formulas inferred from our computer hydrocode calculations. Often this inertial term is negligible, but for problems in the areas of laser fusion and laser equation of state studies we find that it can substantially reduce the attainable hydrodynamic efficiency of acceleration and implosion.
Date: July 15, 1983
Creator: Harrach, R.J.; Szeoke, A. & Howard, W.M.
System: The UNT Digital Library
Relationships between strength, electrical conductivity, and density for oxidized PGX graphite (open access)

Relationships between strength, electrical conductivity, and density for oxidized PGX graphite

The core of a High Temperature Gas-Cooled Reactor (HTGR) rests on massive graphite core support blocks; which, in turn, are supported by core support posts. PGX graphite was used for the core support blocks of the Fort St. Vrain HTGR (the only operating HTGR); and, evidently, is the leading candidate material for use in advanced HTGRs. Therefore, PGX was chosen for the initial tests on the use of eddy current techniques to monitor strength changes as a result of oxidation. The results of these initial tests showed that both compressive strength and electrical conductivity correlated very well with density. However, only a single log of PGX was used for the initial tests; therefore, it was necessary to determine if the correlations could be extended to other logs of PGX.
Date: July 1, 1983
Creator: Morgan, W. C. & Prince, J. M.
System: The UNT Digital Library
New particles and interactions (open access)

New particles and interactions

It is intended to indicate how multiparticle dynamics might serve as a valuable means of advancing our knowledge down the more fundamental line of elementary particle physics. The point of view is taken that the Standard SU(3) x SU(2) x U(1) Model is well established, and is now ripe to be used as a tool for analyzing physics beyond the Standard Model. The tool kit should include reliable and efficient ways of distinguishing gluon jets from quark jets, and of discriminating between t,b,c and light quark jets. What the author considers to be the most topical physics issues arising from the recent confirmation of the Standard Model are reviewed. These include the need for dynamical principles which go beyond the gauge princple, and in particular a satisfactory mechanism for gauge symmetry breaking. Some of the ideas proposed for solving these problems, such as technicolor and supersymmetry (SUSY), are reviewed, together with some of the experimental tests that can be performed. SUSY is examined in detail, and some ways of looking for sparticles in e/sup +/e/sup -/ and anti pp collisions are discussed. The author tries to emphasize the crucial role to be played by the multiparticle jet tools in resolving …
Date: July 1, 1983
Creator: Ellis, J.
System: The UNT Digital Library
Quantitative determination of minerals in Nevada Test Site samples by x-ray diffraction (open access)

Quantitative determination of minerals in Nevada Test Site samples by x-ray diffraction

The external standard intensity ratio technique has been developed into a routine procedure for quantitatively determining mineralogic compositions of Nevada Test Site (NTS) samples by x-ray diffraction. This technique used ratios of x-ray intensity peaks from the same run which eliminates many possible errors. Constants have been determined for each of thirteen minerals commonly found in NTS samples - quartz, montmorillonite, illite, clinoptilolite, cristobalite, feldspars, calcite, dolomite, hornblende, kaolinite, muscovite, biotite, and amorphous glass. Ratios of the highest intensity peak of each mineral to be quantified in the sample and the highest intensity peak of quartz are used to calculate sample composition. The technique has been tested on samples with three to eleven components representative of geologic environments at NTS, and is accurate to 7.0 wt % of the total sample. The minimum amount of each of these minerals detectable by x-ray diffraction has also been determined. QUANTS is a computer code that calculates mineral contents and produces a report sheet. Constants for minerals in NTS samples other than those listed above can easily be determined, and added to QUANTS at any time.
Date: July 1, 1983
Creator: Pawloski, G.A.
System: The UNT Digital Library
Novel neutralized-beam intense neutron source for fusion technology development (open access)

Novel neutralized-beam intense neutron source for fusion technology development

We describe a neutralized-beam intense neutron source (NBINS) as a relevant application of fusion technology for the type of high-current ion sources and neutral beamlines now being developed for heating and fueling of magnetic-fusion-energy confinement systems. This near-term application would support parallel development of highly reliable steady-state higher-voltage neutral D/sup 0/ and T/sup 0/ beams and provide a relatively inexpensive source of fusion neutrons for materials testing at up to reactor-like wall conditions. Beam-target examples described incude a 50-A mixed D-T total (ions plus neutrals) space-charge-neutralized beam at 120 keV incident on a liquid Li drive-in target, or a 50-A T/sup 0/ + T/sup +/ space-charge-neutralized beam incident on either a LiD or gas D/sub 2/ target with calculated 14-MeV neutron yields of 2 x 10/sup 15//s, 7 x 10/sup 15//s, or 1.6 x 10/sup 16//s, respectively. The severe local heat loading on the target surface is expected to limit the allowed beam focus and minimum target size to greater than or equal to 25 cm/sup 2/.
Date: July 8, 1983
Creator: Osher, J.E. & Perkins, L.J.
System: The UNT Digital Library
Search for Inclusive Oscillations of Muon Neutrinos in the Mass Range, 20 <. Delta. M/sup 2/ < 900 Ev/sup 2/ (open access)

Search for Inclusive Oscillations of Muon Neutrinos in the Mass Range, 20 <. Delta. M/sup 2/ < 900 Ev/sup 2/

A sensitive search for inclusive neutrino oscillations has been performed using two similar detectors running simultaneously at different locations in the Fermilab dichromatic muon-neutrino beam. The preliminary results show no significant oscillation signal and rule out inclusive oscillations of muon neutrinos into any other type of neutrons for 20 < ..delta..m/sup 2/ < 900 eV/sup 2/ and sin/sup 2/(2 theta) > 0.03 to 0.10.
Date: July 1, 1983
Creator: Haber, C.; Auchincloss, P.; Blair, R.; Ruiz, M.; Sciulli, F.; Shaevitz, M. et al.
System: The UNT Digital Library